Moir's recently launched a new-flavoured pudding. The marketing manager now wants to assess the product's success in the marketplace. If average sales per week are less than R5 500 per outlet, the product will be withdrawn. The results from a sample of 18 supermarket outlets countrywide showed that average sales per week were R5 275, with a sample standard deviation of R788. Assume weekly sales are normally distributed.

(a) Should the new pudding flavour be withdrawn? Advise the marketing manager by performing an appropriate hypothesis test at the 10% level of significance. Also show the null and alternative hypothesis for this test.

(b) Use Excel's TDIST function to find the p-value for this test. Interpret the findings for the marketing manager.